This project addresses the reciprocal relationship between population and environment in frontier areas of the Brazilian Amazon by focusing on the linked processes of social, economic, demographic, and environmental change. In earlier studies we examined the role of the domestic cycle on land use and distinguished between period and cohort effects, and discovered that a property cycle explained more of the dynamics of change in land cover than a household cycle, particularly after the first generation. In this phase of the study we use as a unifying conceptual framework Forest Transition Theory, and expand our focus to address the role played by the social and economic integration of urban and rural areas, and the growing role of capital investment in large-scale mechanized agriculture and ranching that appears to be transforming the landscape. We examine land use and land cover change at the property and regional level, and focus on two mechanisms posited by Forest Transition Theory to link economic development and forest cover change: migration and agricultural intensification. In the previous phase, we conducted follow up surveys in previously surveyed households and properties at our first study site (Altamira). In this phase, we will carry out follow up surveys in previously surveyed households and properties in Santarim (our second study site), add urban samples for each of these two previously studied areas (Altamira and Santarem), and add a new study site in the epicenter of mechanized soybean expansion in the state of Mato Grosso, at Lucas do Rio Verde where we will sample both large scale rural and urban residents. We will acquire satellite date to update the coverage for the two previously studied areas, and a complete set of data for the past 30 years of change in the new study site as we propose a strong comparative design that will allow us to make inferences about the role of endogenous and exogenous factors in household, property, and landscape dynamics. The use of Forest Transition Theory will help extend the applicability of findings to other frontier regions. With the additional study area, this will be the largest social survey carried out in the Amazon region, with more than 1,000 properties and more than 2,500 households, covering an area in excess of 10,000 square kilometers. PUBLIC HEALTH RELEVANCE: This project explores the social and economic processes associated with land use and land cover change, particularly deforestation, in the Brazilian Amazon. Local impacts include increases in malaria, increases in temperature (with adverse health impacts in a tropical climate), and changes in precipitation patterns (potentially decreasing the availability of clean water). Global impacts, through effects on the global carbon budget, include adverse health impacts of severe weather events and climate changes impacting directly on human health and indirectly through declining agricultural productivity.